icing on the cake

English

icing on the cake

(idiomatic) Something that intensifies the appreciation of something already good.
We went out for dinner and dancing and the icing on the cake was when my boyfriend proposed to me as we danced.
- 2013, Alison Kent, The Icing on the Cake, Hachette UK (→ISBN)
  “I'm happy right now. I don't need to test-drive a bunch of lemons to get me there. But happily ever after? That's a trip worth taking. The pièce de résistance. The crème de la crème. The—” “The icing on the cake,” Dana said. Michelle raised her glass in a toast. “Exactly.”

something that intensifies the appreciation of something else

Catalan: la cirereta del pastís (literally “the small cherry on the cake”)
Chinese:
Mandarin: 锦上添花 (zh) (jǐnshàngtiānhuā)
Czech: třešnička na dortu
Danish: prikken over i'et
Faroese: rosinan í pylsuendanum f
Finnish: sokerina pohjalla (literally “sugar at the bottom”)
French: cerise sur le gâteau (fr) f (literally “cherry on the cake”)
German: Sahnehäubchen n (literally “icing”), das Sahnehäubchen auf dem Kuchen n (literally “the icing on the cake”), das Tüpfelchen auf dem I
Hebrew: הדובדבן שבקצפת‎ (he) m (haduvdeván shebakatséfet, literally “the cherry that's in the whipped cream”)
Hungarian: hab a tortán (literally “whipped cream on the cake”)
Icelandic: rúsínan í pylsuendanum f
Irish: an dlaíóg mhullaigh f (literally "the little wisp on top")
Italian: la ciliegina sulla torta f (literally “the (little) cherry on the cake”)

Norwegian: prikken over i'en (literally “the dot above the i”)
Polish: wisienka na torcie (pl) f (literally “the cherry on the cake”)
Portuguese: a cereja do bolo (pt) f
Romanian: cireașa de pe tort (literally “the cherry on the cake”)
Russian: ви́шенка на то́рте (ru) f (víšenka na tórte) (the cherry on the cake)
Spanish: la guinda del pastel f (literally “the cherry on the cake”)
Swedish: grädde på moset (sv) n (literally “the cream on the mash”), pricken över i:et (sv) c (literally “the dot above the i”)